gh-160386: Apply changes from importlib_metadata 9.1

Lib/importlib/metadata/__init__.py

@@ -22,7 +22,7 @@
 import sys
 import textwrap
 import types
-from collections.abc import Iterable, Mapping
+from collections.abc import Callable, Iterable, Mapping
 from contextlib import suppress
 from importlib import import_module
 from importlib.abc import MetaPathFinder
@@ -35,15 +35,14 @@
 from ._functools import method_cache, noop, pass_none, passthrough
 from ._itertools import always_iterable, bucket, unique_everseen
 from ._meta import PackageMetadata, SimplePath
-from ._typing import md_none
 
 __all__ = [
     'Distribution',
     'DistributionFinder',
+    'MetadataNotFound',
     'PackageMetadata',
     'PackageNotFoundError',
     'PackagePath',
-    'MetadataNotFound',
     'SimplePath',
     'distribution',
     'distributions',
@@ -175,9 +174,11 @@ class EntryPoint:
     ...
     ValueError: ('Invalid object reference...invalid-name...
 
-    The same thing happens on construction.
+    Construction never raises; the value is validated only when
+    accessed or loaded.
 
-    >>> EntryPoint(name=None, group=None, value='invalid-name')
+    >>> ep = EntryPoint(name=None, group=None, value='invalid-name')
+    >>> ep.load()
     Traceback (most recent call last):
     ...
     ValueError: ('Invalid object reference...invalid-name...
@@ -213,7 +214,6 @@ class EntryPoint:
 
     def __init__(self, name: str, value: str, group: str) -> None:
         vars(self).update(name=name, value=value, group=group)
-        self.module
 
     def load(self) -> Any:
         """Load the entry point from its definition. If only a module
@@ -335,7 +335,7 @@ def __repr__(self):
         Repr with classname and tuple constructor to
         signal that we deviate from regular tuple behavior.
         """
-        return '%s(%r)' % (self.__class__.__name__, tuple(self))
+        return f'{self.__class__.__name__}({tuple(self)!r})'
 
     def select(self, **params) -> EntryPoints:
         """
@@ -396,6 +396,25 @@ def __repr__(self) -> str:
         return f'<FileHash mode: {self.mode} value: {self.value}>'
 
 
+def _identify_dist(
+    accessor: Callable[[Distribution], str],
+) -> Callable[[Distribution], str]:
+    """
+    Decorate a required metadata accessor to identify the distribution
+    in the error raised when its field is absent.
+    """
+
+    @functools.wraps(accessor)
+    def wrapper(self: Distribution) -> str:
+        try:
+            return accessor(self)
+        except KeyError as exc:
+            (field,) = exc.args
+            raise KeyError(f'Metadata field {field} not present in {self}') from None
+
+    return wrapper
+
+
 class Distribution(metaclass=abc.ABCMeta):
     """
     An abstract Python distribution package.
@@ -556,6 +575,7 @@ def _ensure_metadata_present(self, text: str | None) -> str:
         raise MetadataNotFound('No package metadata was found.')
 
     @property
+    @_identify_dist
     def name(self) -> str:
         """Return the 'Name' metadata for the distribution package."""
         return self.metadata['Name']
@@ -566,6 +586,7 @@ def _normalized_name(self):
         return Prepared.normalize(self.name)
 
     @property
+    @_identify_dist
     def version(self) -> str:
         """Return the 'Version' metadata for the distribution package."""
         return self.metadata['Version']
@@ -707,7 +728,7 @@ def make_condition(name):
 
         def quoted_marker(section):
             section = section or ''
-            extra, sep, markers = section.partition(':')
+            extra, _sep, markers = section.partition(':')
             if extra and markers:
                 markers = f'({markers})'
             conditions = list(filter(None, [markers, make_condition(extra)]))
@@ -832,7 +853,7 @@ class FastPath:
     """
 
     @_clear_after_fork  # type: ignore[misc]
-    @functools.lru_cache()
+    @functools.lru_cache
     def __new__(cls, root):
         return super().__new__(cls)
 
@@ -885,14 +906,22 @@ def __init__(self, path: FastPath):
         From the children in the path, calculate early all of the
         children that appear to represent metadata (infos) or legacy
         metadata (eggs).
+
+        Children are considered in reverse lexicographic order, so when
+        a path supplies more than one metadata directory for a
+        distribution, as an interrupted or unclean upgrade may leave
+        behind, the greater one is found first
+        (python/cpython#100666). Because the order is lexicographic on
+        the directory name and not on the parsed version, it only
+        approximates a preference for the newer version.
         """
 
         base = os.path.basename(path.root).lower()
         base_is_egg = base.endswith(".egg")
         self.infos = FreezableDefaultDict(list)
         self.eggs = FreezableDefaultDict(list)
 
-        for child in path.children():
+        for child in sorted(path.children(), key=str.lower, reverse=True):
             low = child.lower()
             if low.endswith((".dist-info", ".egg-info")):
                 # rpartition is faster than splitext and suitable for this purpose.
@@ -958,15 +987,8 @@ def __init__(self, name: str | None):
     def normalize(name):
         """
         PEP 503 normalization plus dashes as underscores.
-
-        Specifically avoids ``re.sub`` as prescribed for performance
-        benefits (see python/cpython#143658).
         """
-        value = name.lower().replace("-", "_").replace(".", "_")
-        # Condense repeats
-        while "__" in value:
-            value = value.replace("__", "_")
-        return value
+        return re.sub(r"[-_.]+", "-", name).lower().replace('-', '_')
 
     @staticmethod
     def legacy_normalize(name):
@@ -1017,6 +1039,16 @@ def __init__(self, path: SimplePath) -> None:
         """
         self._path = path
 
+    def __str__(self) -> str:
+        """
+        Render as the metadata path, identifying the distribution
+        even when its metadata cannot name it.
+
+        >>> str(Distribution.at('foo-1.0.dist-info'))
+        'foo-1.0.dist-info'
+        """
+        return str(self._path)
+
     def read_text(self, filename: str | os.PathLike[str]) -> str | None:
         with suppress(
             FileNotFoundError,
@@ -1060,7 +1092,7 @@ def _name_from_stem(stem):
         filename, ext = os.path.splitext(stem)
         if ext not in ('.dist-info', '.egg-info'):
             return
-        name, sep, rest = filename.partition('-')
+        name, _sep, _rest = filename.partition('-')
         return name
 
 

Lib/importlib/metadata/_adapters.py

@@ -54,7 +54,7 @@ class Message(email.message.Message):
     <BLANKLINE>
     """
 
-    multiple_use_keys = set(
+    multiple_use_keys = frozenset(
         map(
             FoldedCase,
             [

Lib/importlib/metadata/_meta.py

@@ -54,11 +54,11 @@ class SimplePath(Protocol):
     """
 
     def joinpath(
-        self, other: str | os.PathLike[str]
+        self, other: str | os.PathLike[str], /
     ) -> SimplePath: ...  # pragma: no cover
 
     def __truediv__(
-        self, other: str | os.PathLike[str]
+        self, other: str | os.PathLike[str], /
     ) -> SimplePath: ...  # pragma: no cover
 
     @property

Lib/importlib/metadata/_text.py

@@ -95,5 +95,5 @@ def index(self, sub):
         return self.lower().index(sub.lower())
 
     def split(self, splitter=' ', maxsplit=0):
-        pattern = re.compile(re.escape(splitter), re.I)
+        pattern = re.compile(re.escape(splitter), re.IGNORECASE)
         return pattern.split(self, maxsplit)

Lib/importlib/metadata/diagnose.py

@@ -1,6 +1,22 @@
 import sys
 
-from . import Distribution
+from . import Distribution, MetadataNotFound
+
+
+def describe(dist: Distribution) -> str:
+    """
+    Describe the distribution by name, or by location when the
+    distribution is too invalid to name itself.
+
+    >>> describe(Distribution.at('missing-1.0.dist-info'))
+    'missing-1.0.dist-info (no metadata)'
+    """
+    try:
+        return dist.name
+    except MetadataNotFound:
+        return f'{dist} (no metadata)'
+    except KeyError:
+        return f'{dist} (metadata without a name)'
 
 
 def inspect(path):
@@ -9,7 +25,7 @@ def inspect(path):
     if not dists:
         return
     print("Found", len(dists), "packages:", end=' ')
-    print(', '.join(dist.name for dist in dists))
+    print(', '.join(map(describe, dists)))
 
 
 def run():

Lib/test/test_importlib/metadata/_path.py

@@ -8,7 +8,7 @@
 from typing import TYPE_CHECKING, Protocol, Union, runtime_checkable
 
 if TYPE_CHECKING:
-    from typing_extensions import Self
+    from typing import Self
 
 
 class Symlink(str):